Chapter 2 The Chemistry of the Cell. The Importance of Carbon The Importance of Water The Importance...
-
Upload
ralph-doyle -
Category
Documents
-
view
225 -
download
0
Transcript of Chapter 2 The Chemistry of the Cell. The Importance of Carbon The Importance of Water The Importance...
![Page 1: Chapter 2 The Chemistry of the Cell. The Importance of Carbon The Importance of Water The Importance of Selectively Permeable Membranes The Importance.](https://reader035.fdocuments.us/reader035/viewer/2022062315/5697c0251a28abf838cd567e/html5/thumbnails/1.jpg)
Chapter 2Chapter 2
The Chemistry of the CellThe Chemistry of the Cell
![Page 2: Chapter 2 The Chemistry of the Cell. The Importance of Carbon The Importance of Water The Importance of Selectively Permeable Membranes The Importance.](https://reader035.fdocuments.us/reader035/viewer/2022062315/5697c0251a28abf838cd567e/html5/thumbnails/2.jpg)
The Chemistry of the Cell
• The Importance of Carbon
• The Importance of Water
• The Importance of Selectively Permeable Membranes
• The Importance of Synthesis by Polymerization of small molecules
• The Importance of Self-Assembly
![Page 3: Chapter 2 The Chemistry of the Cell. The Importance of Carbon The Importance of Water The Importance of Selectively Permeable Membranes The Importance.](https://reader035.fdocuments.us/reader035/viewer/2022062315/5697c0251a28abf838cd567e/html5/thumbnails/3.jpg)
The Importance of Carbon
• The most important atom in biological molecules
• Form covalent bonds with one another and with O, H, N, and S– Single bond– Double bond– Triple bond
![Page 4: Chapter 2 The Chemistry of the Cell. The Importance of Carbon The Importance of Water The Importance of Selectively Permeable Membranes The Importance.](https://reader035.fdocuments.us/reader035/viewer/2022062315/5697c0251a28abf838cd567e/html5/thumbnails/4.jpg)
Carbon-Containing Molecules Are Diverse
![Page 5: Chapter 2 The Chemistry of the Cell. The Importance of Carbon The Importance of Water The Importance of Selectively Permeable Membranes The Importance.](https://reader035.fdocuments.us/reader035/viewer/2022062315/5697c0251a28abf838cd567e/html5/thumbnails/5.jpg)
Carbon-Containing Molecules Can Form Stereoisomers(立體異構
物)
![Page 6: Chapter 2 The Chemistry of the Cell. The Importance of Carbon The Importance of Water The Importance of Selectively Permeable Membranes The Importance.](https://reader035.fdocuments.us/reader035/viewer/2022062315/5697c0251a28abf838cd567e/html5/thumbnails/6.jpg)
The Chemistry of the Cell
• The Importance of Carbon
• The Importance of Water
• The Importance of Selectively Permeable Membranes
• The Importance of Synthesis by Polymerization of small molecules
• The Importance of Self-Assembly
![Page 7: Chapter 2 The Chemistry of the Cell. The Importance of Carbon The Importance of Water The Importance of Selectively Permeable Membranes The Importance.](https://reader035.fdocuments.us/reader035/viewer/2022062315/5697c0251a28abf838cd567e/html5/thumbnails/7.jpg)
The Importance of Water
• Suitable as the universal solvent of living system
• Is the single most abundant component of cells and organisms (75 –85%)
![Page 8: Chapter 2 The Chemistry of the Cell. The Importance of Carbon The Importance of Water The Importance of Selectively Permeable Membranes The Importance.](https://reader035.fdocuments.us/reader035/viewer/2022062315/5697c0251a28abf838cd567e/html5/thumbnails/8.jpg)
The Importance of Water
• Water molecules are polar
• Water molecules are cohesive
• Water has a high temperature-stabilizing capacity
• Water are excellent solvent
![Page 9: Chapter 2 The Chemistry of the Cell. The Importance of Carbon The Importance of Water The Importance of Selectively Permeable Membranes The Importance.](https://reader035.fdocuments.us/reader035/viewer/2022062315/5697c0251a28abf838cd567e/html5/thumbnails/9.jpg)
Water Has a High Temperature-Stabilizing Capacity
• Specific heat (比熱 ): absorb per gram to increase 1 oC
• Specific heat is much higher than other liquid- hydrogen bond
![Page 10: Chapter 2 The Chemistry of the Cell. The Importance of Carbon The Importance of Water The Importance of Selectively Permeable Membranes The Importance.](https://reader035.fdocuments.us/reader035/viewer/2022062315/5697c0251a28abf838cd567e/html5/thumbnails/10.jpg)
Find Out the Terms
• Hydrophilic molecule
• Hydrophobic molecule
• Amphipathic molecule
![Page 11: Chapter 2 The Chemistry of the Cell. The Importance of Carbon The Importance of Water The Importance of Selectively Permeable Membranes The Importance.](https://reader035.fdocuments.us/reader035/viewer/2022062315/5697c0251a28abf838cd567e/html5/thumbnails/11.jpg)
The Chemistry of the Cell
• The Importance of Carbon
• The Importance of Water
• The Importance of Selectively Permeable Membranes
• The Importance of Synthesis by Polymerization of small molecules
• The Importance of Self-Assembly
![Page 12: Chapter 2 The Chemistry of the Cell. The Importance of Carbon The Importance of Water The Importance of Selectively Permeable Membranes The Importance.](https://reader035.fdocuments.us/reader035/viewer/2022062315/5697c0251a28abf838cd567e/html5/thumbnails/12.jpg)
The Importance of Selectively Permeable Membranes
• A membrane is a lipid bilayer with proteins embedded it
• Membranes are selectively permeable
![Page 13: Chapter 2 The Chemistry of the Cell. The Importance of Carbon The Importance of Water The Importance of Selectively Permeable Membranes The Importance.](https://reader035.fdocuments.us/reader035/viewer/2022062315/5697c0251a28abf838cd567e/html5/thumbnails/13.jpg)
Membrane
• Is essentially a hydrophobic permeability barrier
• Consists of phospholipids, glycolipids and proteins
![Page 14: Chapter 2 The Chemistry of the Cell. The Importance of Carbon The Importance of Water The Importance of Selectively Permeable Membranes The Importance.](https://reader035.fdocuments.us/reader035/viewer/2022062315/5697c0251a28abf838cd567e/html5/thumbnails/14.jpg)
Membranes Are Selectively Permeable
• Non-polar: O2, CO2
• Polar: urea, ethanol, H2O
• A least 108 time less permeable to small cation Na+, K+
• Large molecules- Transport protein- a transmembrane protein– Serves either as hydrophilic channel or as
carrier
![Page 15: Chapter 2 The Chemistry of the Cell. The Importance of Carbon The Importance of Water The Importance of Selectively Permeable Membranes The Importance.](https://reader035.fdocuments.us/reader035/viewer/2022062315/5697c0251a28abf838cd567e/html5/thumbnails/15.jpg)
The Chemistry of the Cell
• The Importance of Carbon
• The Importance of Water
• The Importance of Selectively Permeable Membranes
• The Importance of Synthesis by Polymerization of small molecules
• The Importance of Self-Assembly
![Page 16: Chapter 2 The Chemistry of the Cell. The Importance of Carbon The Importance of Water The Importance of Selectively Permeable Membranes The Importance.](https://reader035.fdocuments.us/reader035/viewer/2022062315/5697c0251a28abf838cd567e/html5/thumbnails/16.jpg)
The importance of Synthesis by Polymerization
• Macromolecules are responsible for most of the form and function in living systems
• Cell contain three different kinds of macromolecules
• Macromolecules are synthesized by stepwise polymerization of monomers
![Page 17: Chapter 2 The Chemistry of the Cell. The Importance of Carbon The Importance of Water The Importance of Selectively Permeable Membranes The Importance.](https://reader035.fdocuments.us/reader035/viewer/2022062315/5697c0251a28abf838cd567e/html5/thumbnails/17.jpg)
Macromolecules
• Nucleic acids
• Proteins
• Lipids
• Polysaccharides
![Page 18: Chapter 2 The Chemistry of the Cell. The Importance of Carbon The Importance of Water The Importance of Selectively Permeable Membranes The Importance.](https://reader035.fdocuments.us/reader035/viewer/2022062315/5697c0251a28abf838cd567e/html5/thumbnails/18.jpg)
Macromolecules are Responsible for Most of the Form and Function in Living Systems
• Macromolecules are very important in both the function and the structure of the cells– Cell wall: cellulose – repeating polymer of the
glucose– The macromolecules that are responsible for
most form and other characteristic of living system are generated by the polymerization of small organic molecules
![Page 19: Chapter 2 The Chemistry of the Cell. The Importance of Carbon The Importance of Water The Importance of Selectively Permeable Membranes The Importance.](https://reader035.fdocuments.us/reader035/viewer/2022062315/5697c0251a28abf838cd567e/html5/thumbnails/19.jpg)
The Chemistry of the Cell
• The Importance of Carbon
• The Importance of Water
• The Importance of Selectively Permeable Membranes
• The Importance of Synthesis by Polymerization of small molecules
• The Importance of Self-Assembly
![Page 20: Chapter 2 The Chemistry of the Cell. The Importance of Carbon The Importance of Water The Importance of Selectively Permeable Membranes The Importance.](https://reader035.fdocuments.us/reader035/viewer/2022062315/5697c0251a28abf838cd567e/html5/thumbnails/20.jpg)
To be Functional Protein
• Protein need to fold properly:
– linear polypeptide chains must coil and fold in very precise
– Effects: pH, Temp, highly acidic or alkaline
• The denaturation or renaturation of ribonuclease
![Page 21: Chapter 2 The Chemistry of the Cell. The Importance of Carbon The Importance of Water The Importance of Selectively Permeable Membranes The Importance.](https://reader035.fdocuments.us/reader035/viewer/2022062315/5697c0251a28abf838cd567e/html5/thumbnails/21.jpg)
Molecular Chaperones Assist the Assembly of Some Protein
• The self-assemble model may not adequate for all proteins- – molecular chaperones could help to reduce
the incorrect structure - assist self-assembly
• Strict self-assembly and assist self-assembly
• Molecular Chaperones– a protein that facilitates the folding of other
proteins– Heat-shock protein
![Page 22: Chapter 2 The Chemistry of the Cell. The Importance of Carbon The Importance of Water The Importance of Selectively Permeable Membranes The Importance.](https://reader035.fdocuments.us/reader035/viewer/2022062315/5697c0251a28abf838cd567e/html5/thumbnails/22.jpg)
Noncovalent Interactions Are Important in the Folding of Macromolecules
• Covalent bone– Not only link the monomers of a polypeptide,
also stabilize the three dimensional structure of many protein: S-S bond
• Non-covalent bond– Most of the structures in the cells are held
together by much weaker forces- within and between proteins and macromolecules
• H-bond, ionic bonds, van der Waals interactions, hydrophobic interactions (p46)
![Page 23: Chapter 2 The Chemistry of the Cell. The Importance of Carbon The Importance of Water The Importance of Selectively Permeable Membranes The Importance.](https://reader035.fdocuments.us/reader035/viewer/2022062315/5697c0251a28abf838cd567e/html5/thumbnails/23.jpg)
Self-Assembly Also Occurs in Other Cellular Structures
• Ribosomes
• Membrane
• …...
![Page 24: Chapter 2 The Chemistry of the Cell. The Importance of Carbon The Importance of Water The Importance of Selectively Permeable Membranes The Importance.](https://reader035.fdocuments.us/reader035/viewer/2022062315/5697c0251a28abf838cd567e/html5/thumbnails/24.jpg)
Self-Assembly Has Limits
• Some assembly system depend on information supplied by a pre-existing structure– by adding new material to existing sturcture– membrane, cell wall, chromosomes
![Page 25: Chapter 2 The Chemistry of the Cell. The Importance of Carbon The Importance of Water The Importance of Selectively Permeable Membranes The Importance.](https://reader035.fdocuments.us/reader035/viewer/2022062315/5697c0251a28abf838cd567e/html5/thumbnails/25.jpg)
Hierarchical Assembly Provides Advantages for the Cells
• Biological structures are almost always constructed in a hierarchical (等級)manner
• Hierarchical process- two advantages– Chemical simplicity
• Almost all structures found in cells are synthesized from about 30 small precursor molecules (Table 3-1)
– Quality control• allow defective components to be
discarded at an early stage